controller cutoff

[shakkan]

ive just come back from a ride and the bike was cutting out after 13.3(21.7km) miles-ive got a ping 36v 16amp ilfe04  battery. the battery was not ballancing propley, so I contacted ping and was told the battery didnt ballance(every cell was different and all above 3.1v)  because it was not fully charging. The charge voltage was 41volts ,so ping told me to adjust to 45volts which I did and the battery ballanced at 3.7v each.Ive just checked the battery and it is 38v after the ride-13.5miles.
Q:do my numbers seem right,ie-36v battery reading 45v
Q:13.3 miles =38v
Q:is the controller cutoff piont 30v,if so why cut at 38v
Q: is the cutoff on the controller adjustable
thanx

[biohazardman]

Although 45 v seems a bit high of a charge I would expect the BMS is not putting that all of that into the battery?

To many variables to guestimate the mileage you should get at that voltage.  Weight, rolling resistance, hills, wind, speed and how quickly you start up as well as if you help by pedaling all come into play.

Voltage sag happens when you open up the throttle under load.  I expect that is why you are going into the Low Voltage Cutoff area of the controller. The more amperage the batteries can output the less sag you will have. The quality or your connections as well as wire size also can affect voltage also.

Some controllers probly have adjustable cutoff by now most do not and components often resistors on the controller must be changed.

[shakkan]

the battery does read 45v after charging and its a gm standard controller.
i pedal all the time and allways from a start.
will check all the connections tomorrow.

[Mel in HI]

Regarding the controller cutoff at a higher voltage, if you stop and measure the voltage while not under load, it's possible that the voltage might have gone temporarily lower and recovered not under load.  But I thought that was more common under LeadAcid. 

This thread does remind me of another thread where they found that the connector to the battery was not tight and it was shutting down after a bump.  Are any of the connectors hot/warm after you have ridden for a while?  Do any of them seem loose/easily disconnected?  Sorry Bio, I was just trying to expand on what you already said. 

[shakkan]

got 11miles this time and the battery voltage was 39.1v. question is ,is it the controller cutting out or the bms on battery.
all conections are good and nothing was hot at failure time.
when the bike cuts out ALL the lights go out on the twist grip power indicator.and I have to switch off the relay and on again to power up again.
Q:would the lights stay on the power grip even if the cutoff point was reached(from controller)
Q: how would I test the controller/battery at the time of cutout
thanx

[biohazardman]

Likely it is the battery as stated before. Hook a volt meter up to the batts and go for a ride.  Watch the voltage at cut off time.  Likely you have a bad cell or two as that is the most common failure. Good luck 

[shakkan]

contacted Li Ping and was told to check voltage of cells after the bms cut out. One cell had.1v.
Told ping and he is sending out replacement cells.Answered straite away so feel much better now. Has anybody replaced cells from a duck tape battery?

[TOM]

cut off not only controller
if your battery have safe protect,in lower voltage,
your battery can prevent controller working,in order to protect your battery